lastly vs someday

lastly

adv
  • Used to signal that the speaker is about to yield control of the conversation. 

  • Used to mark the beginning of the last in a list of items or propositions. 

someday

adv
  • Sometime; at some unspecified time in the future. 

How often have the words lastly and someday occurred in a corpus of books? (source: Google Ngram Viewer )